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Case Reports
. 2008 May;29(5):875-82.
doi: 10.3174/ajnr.A0950. Epub 2008 Feb 13.

High-resolution CT imaging of carotid artery atherosclerotic plaques

M Wintermark  1 , S S Jawadi, J H Rapp, T Tihan, E Tong, D V Glidden, S Abedin, S Schaeffer, G Acevedo-Bolton, B Boudignon, B Orwoll, X Pan, D Saloner
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Case Reports

High-resolution CT imaging of carotid artery atherosclerotic plaques

M Wintermark et al. AJNR Am J Neuroradiol. 2008 May.

Abstract

Background and purpose: Plaque morphologic features have been suggested as a complement to luminal narrowing measurements for assessing the risk of stroke associated with carotid atherosclerotic disease, giving rise to the concept of "vulnerable plaque." The purpose of this study was to evaluate the ability of multidetector-row CT angiography (CTA) to assess the composition and characteristics of carotid artery atherosclerotic plaques with use of histologic examination as the gold standard.

Materials and methods: Eight patients with transient ischemic attacks who underwent carotid CTA and "en bloc" endarterectomy were enrolled in a prospective study. An ex vivo micro-CT study of each endarterectomy specimen was obtained, followed by histologic examination. A systematic comparison of CTA images with histologic sections and micro-CT images was performed to determine the CT attenuation associated with each component of the atherosclerotic plaques. A computer algorithm was subsequently developed that automatically identifies the components of the carotid atherosclerotic plaques, based on the density of each pixel. A neuroradiologist's reading of this computer analysis was compared with the interpretation of the histologic slides by a pathologist with respect to the types and characteristics of the carotid plaques.

Results: There was a 72.6% agreement between CTA and histologic examination in carotid plaque characterization. CTA showed perfect concordance for calcifications. A significant overlap between densities associated with lipid-rich necrotic core, connective tissue, and hemorrhage limited the reliability of individual pixel readings to identify these components. However, CTA showed good correlation with histologic examination for large lipid cores (kappa = 0.796; P < .001) and large hemorrhages (kappa = 0.712; P = .102). CTA performed well in detecting ulcerations (kappa = 0.855) and in measuring the fibrous cap thickness (R(2) = 0.77; P < .001).

Conclusion: The composition of carotid atherosclerotic plaques determined by CTA reflects plaque composition defined by histologic examination.

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Figures

Fig 1.
Fig 1.
In vivo CTA image of the common carotid artery, and matching ex vivo micro-CT and histologic sections. Automated classification computer algorithm-derived overlay shows lipid-rich necrotic core (yellow), calcification (blue), blood products (red), and remaining connective tissue (green). CTA overlay demonstrates a plaque with a large lipid core, small calcifications, and an ulceration, making it a VIa lesion according to the AHA classification, in agreement with histologic examination, the gold standard for noncalcified carotid wall components, and with ex vivo micro-CT, the reference for carotid wall calcium (specimens were decalcified before histologic sectioning).
Fig 2.
Fig 2.
In vivo CTA image of the ICA, and matching ex vivo micro-CT and histologic sections. Automated classification computer algorithm-derived overlay demonstrates a plaque with sparse “lipid” pixels (yellow) and an ulceration, making it a VIa lesion according to the AHA classification, in agreement with histologic examination.
Fig 3.
Fig 3.
In vivo CTA image of the ICA, and matching ex vivo histologic section. Automated classification computer algorithm-derived overlay demonstrates a plaque with a superficial calcification (blue), making it a Vc lesion according to the AHA classification, in agreement with histologic examination.
Fig 4.
Fig 4.
In vivo CTA image of the ICA, and matching ex vivo histologic section. Automated classification computer algorithm-derived overlay demonstrates a plaque with a large hemorrhage (red), making it a VIb lesion according to the AHA classification, in agreement with histologic examination.
See this image and copyright information in PMC

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References

    1. Beneficial effect of carotid endarterectomy in symptomatic patients with high-grade carotid stenosis. North American Symptomatic Carotid Endarterectomy Trial Collaborators. N Engl J Med 1991;325:445–53 - PubMed
    1. Barnett HJ, Taylor DW, Eliasziw M, et al. Benefit of carotid endarterectomy in patients with symptomatic moderate or severe stenosis. North American Symptomatic Carotid Endarterectomy Trial Collaborators. N Engl J Med 1998;339:1415–25 - PubMed
    1. Randomised trial of endarterectomy for recently symptomatic carotid stenosis: final results of the MRC European Carotid Surgery Trial (ECST). Lancet 1998;351:1379–87 - PubMed
    1. Mayberg MR, Wilson SE, Yatsu F, et al. Carotid endarterectomy and prevention of cerebral ischemia in symptomatic carotid stenosis. Veterans Affairs Cooperative Studies Program 309 Trialist Group. JAMA 1991;266:3289–94 - PubMed
    1. Ebrahim S, Papacosta O, Whincup P, et al. Carotid plaque, intima media thickness, cardiovascular risk factors, and prevalent cardiovascular disease in men and women: the British Regional Heart Study. Stroke 1999;30:841–50 - PubMed

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